карбонатный расплав

The concentrations of the main components of the (Li_0.62K_0.38)₂CO₃ melt have been evaluated by the thermodynamic modeling technique, and the Warburg coefficients of electroactive particles as a function of temperature and CO₂/O₂ gas mixture composition have been calculated. The same dependences of Warburg coefficient and charge transfer resistance were studied on Au cathode using coulostatic technique. It is shown that O₂ ions and O₂ molecules are the main electroactive species in the melt. Their relative concentration determines which reaction mechanism dominates.

The oxygen reduction mechanisms on an oxide electrode are proposed. It was found, that in the temperature range 870–1020 K mechanism involving superoxide ions dominates, whereas in T < 870 К region the reaction mechanisms involving molecular oxygen apparently take place.

The results of the study of kinetics of oxygen reduction on the dense LaLi_0.1Co_0.1Fe_0.8O_3-d electrode in (Li_0.62K_0.38)₂CO₃ eutectic melt using coulostatic technique are reported. It was found, that the equivalent circuit that includes heterogeneous charge transfer step in series with heterogeneous chemical reaction most closely fits the kinetics of electrode processes.